Railhead clamp



May 27, 1947. A. H. GENTER RAIL HEAD CLAMP 'Filed'oct. 4, 1944 Patented May 27, 1947 ZAZLZS? UNETED STATES PATENT OFFICE BAILHEAD CLAW Albert H. Genter, Mount Lebanon, Pa. Application October 4, 1944, Serial No. 557,099 3 Claims. (01. 173 -324) This invention relates generally to rail clamps and more particularly to a clamp for connecting a return circuit cable to the ball or head of a rail.

Mine locomotives are required to gather loaded mine cars from and deliver empty cars to the mining face or loading positions on spur tracks laid in rooms oif the main hall along which electrical power circuits are permanently strung. The rails of the spur tracks are not bonded nor are they supplemented with power and trolley wires. It is therefore necessary for the locomotive to be provided with cables carried on drums or reels for supplying propulsion energy while traveling over these spur tracks. One cable is provided with a trolley wire feeder tap or other similar connection to be attached to a feeder or trolley wire and the other cable is provided with a clamp for attachment to the rail for the return circuit. This invention is directed to the return rail clamp which may be applied by the locomotive engineer without leaving his station on the locomotive.

The principal object of this invention is the provision of a metal return circuit clamp that may be quickly applied and removed from the rail head.

Anothe object is the provision of a metal rail head clamp that tightens on the rail head by the weight and pull of the cable attached thereto.

Another object is the provision of a metal rail clamp that may be applied and released by one hand.

Another object is the pro-vision of a metal rail clamp that is readily adjustable for diiferent size rail heads.

Another object is the provision of a metal rail head clamp having quick acting jaws which move in unison when clamped or unclamped from arail head.

Another object i the provision of a metal rail head clamp that is operable within adjustable defined limits insuring quick positive clamping on a rail head.

Another object is the provision of a pair of rail head clamping jaws that lock on the rail head as the clamping pressure is applied.

Another object is the provision of a lever actuated double movable jaw clamp that may be applied and removed from a rail head in less than 180 swing of the lever.

Other objects and advantages appear in the following description and claims.

A practical embodiment illustrating the prin ciples of this invention is shown on the accompanying drawing wherein:

Fig. 1 is a perspective view of the clamp applied to a rail head.

Fig. 2 is a sectional view taken along the axis of the clamp screw.

Referring to the drawings, the return rail head clamp is assembled on the screw shaft I 0 which is relatively large in diameter and is provided with a right and left hand screw thread II and I2 and an intermediate reduced section I3 between the threads. A pair of jaw members I4 and I5 are provided with aligned holes which are threaded as indicated at I6 and I! to receive the right and left hand threads respectively of the screw shaft I I]. Each jaw member is provided with an upwardly extending boss l8 having a hole I9. When the jaws are threaded on the shaft It and the holes I9 are aligned to receive the bolt 20 which is provided with the nut 2| the bolt 20 maintains the jaw members I4 and I5 in alignment on the shaft I0. The holes I 9 in the bosses I8 are sufliciently large to'pass the bolt 20 but snugly fit the latter to prevent the jaw members from being turned out of substantial alignment on the shaft I i].

Owing to the fact that the shaft threads II and I2 are right and left hand respectively, rotation of the shaft Ill in one direction will draw the jaw members toward one another while rotation of theshaft in the opposite direction will move each jaw member away from one another and from the intermediate reduced section it.

The depending portions of the jaw members I4 and I 5 are provided with gripping faces 22 and 23. Each gripping face is inclined relative to the axis of the shaft to and the longitudinal axis of the jaw members. When the shaft is turned to draw the jaw members together the gripping faces 22 and 23 converge at the lower ends of the jaw members. The lower ends of the jaw members xtend below the rail head and the inclined gripping faces contact the lower edge of the rail head to provide a tight wedging engagement. The clearance between the threaded holes l6 and I1 and the threads II and I2 on the shaft is taken up as the jaw members are tightened on the rail head. But this clearance is not sufiiciently great to make the inclined. gripping faces vertical when the jaw members are clamped on a rail head.

The upper ends of the gripping faces extend into the body of the jaw members forming the shoulders 24 and 25 which rest on thetop of the rail head 26, providing a stop for the insertion of the rail head clamp on the rail.

The shaft ID is provided with squared ends 21 and 28 of hexagon shape to receive the mating socket 29 in the end of the lever 30 which is used to rotate the shaft ID to clamp and unclamp the jaw members to the ball or head of the rail and is also used for the purpose of connecting the cable 34 to the clamp. The lever 30 is thicker than the squared ends of the shaft so that it eX= tends therebeycnd and will be tightly locked in place by the washer 32 and the bolt 33 which is screwed into axially threaded holes in the ends 9f the shaft ID.

The lever is provided with a transverse hele to receive the bolt 35 that tightens the clamping plate 36 on the bared end of the cable 31 that is twisted around the bolt. In this manner the cable 3| is electrically connected to the bail head clfill h A pair of spaced U-bolts 31 and 3 8 are threaded 1 the r end an p ss h g g ed a verse holes in the lever 30. Nuts and washers are provided on the other side of the lever 3!! to clamp the U-bolts down on the insulated section of the cable 3| and hold it in place, thereby relieving the terminal bolt 35 and clamping plate 36 from a pull or tug on the cable 3!.

A stop post 40 is provided with a threaded end for ecuring it into the threaded holes 41 and 42 in the outer face of the jaw members l4 and 15. This step pin extends beyond the end of the shaft l!) and prevents the lever 30 from being rotated through 360 a fixed setting of the jaw members cannot be changed unless the stop pin 40 or one of the two bolts 20 or 33 is removed. If the bolt 20 is removed the clamping jaw not having the stop pin may be rotated in either direction through 360 to adjust the relative positions of the jaw members the distance of one pitch of the threads on the shaft H). To adjust the jaw members adjacent the lever handle in the same manner either the lever and bolt 33 or the stop pin All together with the bolt 20 must be removed. Again the lever may be remove from the squar d end f the shaft ii! a the latter rotated to more both laws simultaneously either direction and adjust t e law members. When replacin h le e 3 th squared end the relat ve notifier-. oi eve an sha t have chan ed t provide a e ecte limit throu h wh ch th laws are o erated to rip a given size rail head by a s ir sw n o th ever 59.- Th sq ar d. ends 21 a d 2! of the sh .1 b in beaten; provide li e ad ust ng posit on it a f ll tu n oi th shaft 1 Th permit the lever 3 o he Pla ed at a angle to th rail wh n t e clam ightly gri s th ra h ad:

lever terms th handle o th r il head clamp :f r he m ning eccmot vs ngineer t ach d wn; ep the Jaws eve the rail ead and draw h le er owards the l co We A th occmctive pleads a ong the tra k the cab e 3' fas en d to t e l v is wir s-l d ir he drum- Anr tug er P1111 on he cable is r nsmit-ted t he l ve a s ng it o fu the t h e t e gr p cf the Jew on t e a adth locom i e rets ns he cable i s ed and th ,I iftme the le er ts the law Rili illk t e ra l their 9 be ed item the rail head without dismognting from the seat th locomotive the slo 9 the gr pping fa es on th Jew memb rs a d t e incli ation of the lever hen h jaw m mbe s a tightly clamped permit quick manipulation of the rail head clamp and provide a positive low resistance contact for the return rail circuit. The constant load created by the pull or drag on the cable maintains the jaw members tightly clamped on the rail head. The bolt 20 maintains the jaw members in proper alignment and the stop pin 40 maintains the selected setting or gauge of the jaw members for a particular rail head size.

.I cl im:

1. A rail clamp for attaching an electric return circuit cable to the head of a rail comprising a screw shaft provided at its opposite extremities with a right hand thread and a left hand thread respectively, a pair of rail headgripping jaws having aligned holes provided respectively with a right hand thread and a left hand thread which are engaged by the corresponding threads of the screw shaft, opposed shoulders on the jaws arranged to engage the top of the rail head and limit the downward movement of the jaws, said jaws having opposed gripping" surfaces which converge downwardly and engag the lower edges of the rail head when the jawsare caused to converge, means for rotating the screw shaft to cause the jaws to grip the rail head or to release the jaws from the rail head, and means for electrically connecting an electric cable to said last mentioned means whereby the pull of the cable tightens the clamp on the ra hea 2 A rail clamp for attaching an electric return circuit cable to the head of a rail comprising a screw shaft provided at its opposite extremiti es with a right hand thread and a left hand thread respectively, a pair of rail head-gripping jaws having aligned holes provided respectively with a right hand thread and a left hand thread which are engaged by the corresponding threads of the screw shaft, opposed shoulders on the laws arranged to engage the top of the rail head and limit the downward movement of the jaws, said jaws having opposed gripping surfaces which converge downwardly and engage the lower edges of the rail head when the laws are caused to converge, means for rotating the screw shaft to cause the jaws to grip the rail head and to release the jaws from the rail head, means for electrically connecting an electric cable to said last mentioned means whereby the pull of the cable tightens the clamp on the rail head, and means for preventing misalignment of the jaws in a plane normal to the axis of the screw shaft.

.3. A rail clamp for attaching an electric return circuit cable to the head of .a rail comprising a screw shaft provided at its opposite .extremities with a right hand thread and .a left hand thread respectively, a pair of rail heade ppi laws having ali ed hol s provided respectively with a right hand thread and left hand thr ad hi h ar n ag d wi h the cor sncnd' ne threads or the screw shaft, oppesed senders on the Jews a ran ed to enga e th top of the rail head to limit the downward n ove m at o he Jaws said Jaw be ng p v ded w reased r pin urf c s ich converse down wardly and en age the l e ed es o the ra head when t e laws a e ensed converse. a le e an n nd ofibe cre she-i rotating the lette means i r el ct ica ly connecting an electric cable said lever whereby th p ll or he able tigh ns the c amp an the rail head, and means for varying the angular re at on the le e to th sc ew shaft w r the engineer of a mining locomotive may attach 6 the clamp to the rail head without dismounting. Numb N m Date ALBERT H. GENTER- 1,591,301 Ford July 6, 1926 1,096,498 Flanary May 12, 1914 REFERENCES CITED 2,060,448 Schwendt et a1. Nov. 10, 1936 The following references are of record in the 5 1,920,543 Carlson 1933 file f this patent; 1,473,946 Amsden Nov. 13, 1923 936,417 Crawford Oct. 12, 1909 UNITED STATES PATENTS 600,324 Strub Mar. 8, 1898 Number Name Date 2,299,291 Zam Oct. 20, 1942 10 

